1. Field of the Invention
This invention generally relates to humidifiers or vaporizers. More specifically, this invention is directed to a warm mist humidifier for use in domestic applications.
2. Description of the Prior Art
Various types of humidifier devices are used to provide moisture to indoor air. Included among such humidifiers are ultrasonic humidifiers, steam humidifiers or vaporizers, warm mist humidifiers and evaporative humidifiers. The beneficial effects of these humidifiers are numerous and include: protection to the respiratory system of the user, reducing dryness and irritation in the user's nose and throat, reduction in static electricity, and protection of wood furniture, paneling and fabrics.
The warm mist type humidifiers have been effectively used to achieve very high humidification levels. Conventional humidifiers of the warm mist type usually produce a warm mist (rather than steam produced by the steam vaporization type humidifiers) into the environment to be humidified. Typical warm mist humidifiers employ an electric heater coil, which is in direct contact with water, for converting water contained in a reservoir into vapor. Additionally, the humidifiers may employ a float switch for activating or deactivating the heating coil based on the water level sensed by the float switch. The vapor in the humidifiers will rise through a vapor passage and mix with air drawn from an electric blower. Alternatively, the vapor can be produced in combination with a vaporized medicament for the treatment of colds, coughs, or other disorders of the respiratory system.
The conventional warm mist humidifier constructed as described above has many disadvantages. For example, minerals in the water are easily deposited on the surface of the heating coil which is made of a metal such as stainless steel or graphite. As a result, the electrical conductivity of the surface of the coil can deteriorate and it is often difficult to clean the stain on the surface of the coil. A float switch typically found in the conventional warm mist humidifier for activating or deactivating the heating coil according to the sensed water can easily deteriorate since it floats on water and is in direct contact with water. Additionally, moist on the heating coil or the float switch can attract potentially harmful microorganisms, thereby creating a higher amount of bacteria count in the mist.